const calculators = {
  S (salary) {
    return salary * 4
  },
  A (salary) {
    return salary * 3
  },
  B (salary) {
    return salary * 2
  },
}

const calculateBonus = (level, salary) => calculators[level](salary)

console.log(calculateBonus('S', 1000))
console.log(calculateBonus('B', 2000))
